Patent Literature 1 discloses that two motors for controlling independently left and right wheels of a vehicle are installed in a back-to-back fashion so that rotational axes of the motors are aligned into the same straight line. As shown in FIG. 14, these two motors 202A, 202B are disposed in positions and forms in which their U-phase connecting points 273u, V-phase connecting points 273v and W-phase connecting points 273w are in mirror symmetry with each other with respect to a middle plane M which is situated between the motors 202A, 202B.